... 20-2It is used for automatic welding of circular welding seam in barrel and axis,such as transmission shah,axle, ... Welder is pneumatic controlled and weldment is on the support rollers. The whloe course of auto-control welding:compacted by tailstock ... mechanical major for the safe operation,reliable quality,smoothly pretty seam and substantially increased work efficiency.Adapting weldor:argon-arc ...